Biofuels and the Environment - CLU-IN

Report
1
Welcome – Thanks for joining
this ITRC Training Class
Biofuels
Biofuels: Release Prevention, Environmental
Behavior, and Remediation
Sponsored by: Interstate Technology and Regulatory Council (www.itrcweb.org)
Hosted by: US EPA Clean Up Information Network (www.cluin.org)
2
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Copyright 2012 Interstate Technology & Regulatory Council,
50 F Street, NW, Suite 350, Washington, DC 20001
3
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This material was sponsored by an agency of the United States Government.
The views and opinions of authors expressed herein do not necessarily state
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4
ITRC (www.itrcweb.org) – Shaping the
Future of Regulatory Acceptance

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Host organization
Network
• State regulators
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•
•
•
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 All 50 states, PR, DC
• Federal partners

DOE
DOD
EPA
• ITRC Industry Affiliates
Program
Wide variety of topics
Technologies
Approaches
Contaminants
Sites
Products
• Technical and regulatory
guidance documents
• Internet-based and
classroom training
• Academia
• Community stakeholders
5
ITRC Course Topics Planned for 2012 –
More information at www.itrcweb.org
Popular courses from 2011
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New in 2012
 Green & Sustainable
Bioavailability Considerations for
Contaminated Sediment Sites
Remediation
Biofuels: Release Prevention, Environmental  Incremental Sampling
Behavior, and Remediation
Methodology
Decision Framework for Applying Attenuation
 Integrated DNAPL Site
Processes to Metals and Radionuclides
Strategy
Development of Performance Specifications
for Solidification/Stabilization
2-Day Classroom Training:
LNAPL 1: An Improved Understanding of
 Light Nonaqueous-Phase
LNAPL Behavior in the Subsurface
Liquids (LNAPLs):
LNAPL 2: LNAPL Characterization and
Science, Management,
Recoverability - Improved Analysis
and Technology
LNAPL 3: Evaluating LNAPL Remedial
Technologies for Achieving Project Goals
October 16-17, 2012 in Novi,
Mine Waste Treatment Technology Selection
Michigan (Detroit Area)
Phytotechnologies
Permeable Reactive Barrier (PRB): Technology Update
Project Risk Management for Site Remediation
Use and Measurement of Mass Flux and Mass Discharge
Use of Risk Assessment in Management of Contaminated Sites
6
Meet the ITRC Instructors
Mike Maddigan
Pennsylvania Department
Environmental
Protection
Harrisburg, PA
717-772-3609
[email protected]
Denice Nelson
ARCADIS-US, Inc.
Minneapolis, MN
612-386-4618
denice.nelson
@arcadis-us.com
David Tsao
Mark Toso
BP
Naperville, IL
630-420-5147
[email protected]
Minnesota Pollution
Control Agency
St. Paul, MN
651-757-2158
mark.toso
@state.mn.us
7
Biofuels and the Environment
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What are biofuels and why are they important?
Are there equipment compatibility issues
associated with biofuels?
How do biofuel releases impact the
environment?
Do biofuels behave differently in the
environment than petroleum-based fuels?
How should biofuels releases be cleaned up?
8
What You Will Learn
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Scope of potential environmental challenges
Differences between biofuel and petroleum fuel
behavior
Biofuel supply chain, potential release scenarios,
and release prevention
How to develop an appropriate conceptual model
for the investigation and remediation of biofuels
Appropriate investigation and remediation
strategies
How to assess the behavior of new biofuels when
alternatives come on the market
9
Training Roadmap
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Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
= hypothetical case study
10
Our Hypothetical Case Study
Dispenser
System
Dispensing
Station
Vadose
Zone
Underground
Storage Tank
System (UST)
Capillary
Fringe
Aquifer
Groundwater
Flow Direction
11
What Are Biofuels?

For the purposes of this
training, the term biofuel is
applied to liquid fuels and
blending components produced
from renewable biomass
feedstocks used as alternative
or supplemental fuels for
internal combustion engines.
12
Important Terms

Denatured Fuel Ethanol (DFE) – fuel ethanol made unfit
for beverage use by the addition of a denaturant; also
called E95.

FAME (Fatty Acid Mono-alkyl or Methyl Esters) –
Transesterified oils derived from vegetable oils or animal
fats, blended with or used in place of conventional diesel
fuels.

Biofuel Blend – Mixture of biofuel and conventional
petroleum-based fuel.

Conventional Fuel – A mixture of compounds, called
hydrocarbons, refined from petroleum crude, plus
additives to improve its stability, control deposit formation
in engines, and modify other characteristics.
13
Why be Concerned with Biofuel
Releases?

Catastrophic impact of
large releases
• Large releases from tank
car train derailments
• Massive fires

Smaller releases
• Slow leaks can go
2009 train derailment in Rockford, IL
resulting in 435,000-gallon DFE release.
undetected (such as in
storage tanks)
• Large volume - severe
environmental impacts
Photos from NTSB
Scorched rail cars after fire in the
Rockford, IL release.
14
Petroleum vs. Biofuel Releases

Behave differently in the
environment
• Site characterization and
remediation strategy
• Safety risks
• Potential release points

For more info on LNAPL
training go to
http://www.itrcweb.org
15
Federal Renewable Fuel Mandates

Energy Policy Act of 2005
• First Renewable Fuel Standard (RFS) program
• Required 7.5 billion gallons of renewable fuel to be
blended into gasoline by 2012

Energy Independence & Security Act of 2007
• Renewable fuel requirements increased
9 billion gallons (2008)

36 billion gallons (2022)
Additional alternative fuel objectives for federal
Alternative Fuel Vehicle (AFV) fleets
16
State Renewable Fuel Mandates
Table 1-3
WA
MT
OR
MN
PA
MO
NM
LA
FL
HI
MA
17
International Mandates

European Union
• Directive 2003/30/EC
• Promotes biofuels use in
transportation sector
• Proposes non-mandatory
biofuels use targets

Brazil
• Has required the use of
biofuels since 1976
18
ITRC Guidance: Biofuels: Release
Prevention, Environmental Behavior, and
Remediation
1. Biofuel basics
2. Release prevention and
response planning
3. Fate & transport (F&T) of
biofuels in the environment
4. Characterizing release
sites
5. Long-term response
strategies
6. Stakeholder concerns
19
What is Not Covered
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Vegetable oils, recycled greases, and fuels
indistinguishable from petroleum-based fuels
Air quality
Sustainability
Detailed information on
manufacturing processes
End-user considerations
Biofuel policies
Fuel additives
20
Applying the ITRC Document Before a
Release

Release prevention
• Ensure materials
compatibility
• Update best management
practices

Release response
planning
• Fire/explosion threats
• Rapid containment
21
Applying the ITRC Document After a
Release

Site characterization, sampling, F&T modeling
• Physical, chemical, and biological properties
• Developing Site Conceptual Model (SCM)
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Long-term responses
• Determining remediation strategy
• Assessing hazards and risks
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Stakeholder concerns
• Location of incident
• Timing of response

Emerging biofuels
• Multi-media evaluation process
22
Ethanol Fuel Blends
(Table 1-1)
ASTM
Standard
No adopted
standard
Fuel
Description
E85
A commercial trade name representing an
alternative fuel consisting of 70%–85% DFE
by volume as defined in the EPAct of 1992
Ethanol fuel
blends for
flexible-fuel
vehicles
Intermediate
ethanol
blends
E10
Fuel produced for use in ground vehicles
equipped with flexible-fuel spark-ignition
engines containing 51%–83% ethanol; may
be referred to at retail as “ethanol flex-fuel”
Intermediate blends of DFE and gasoline
>E10 and <E51
D5798-11
Gasoline with up to 10% DFE by volume
D4814
(standard for
gasoline)
“Neat Ethanol” (E100) is non denatured ethanol
No adopted
standard
23
Biodiesel and Biodiesel Blends
(Table 1-2)
Fuel
Description
ASTM
Standard
B100
Biodiesel fuel blend stock; legally registered as a
fuel and fuel additive with USEPA under Section
211(b) of the Clean Air Act
D6751-11
>B20 to
<B100
A blend of petroleum-distillate and biodiesel fuel
that contains between 21% to 99% biodiesel
No
standard
adopted
>B5 to B20
A blend of petroleum-distillate and biodiesel fuel
that contains between 6% to 20% biodiesel
D7467-10
Up to B5
Fuel blends of up to 5% biodiesel fuel are
considered a fungible component of conventional
petroleum-based diesel fuel
D975
(same as
petroleum
standard)
“Neat Biodiesel” is biodiesel not blended with petroleum-based diesel and is
designated as “B100”
24
Biofuel Production Projections
(Figures 1-1 and 1-2)
World Ethanol Production
Projections
(millions of gallons)
35,000
25,000
15,000
World Biodiesel Production
Projections
(millions of gallons)
6,000
5,000
4,000
3,000
25
Opportunities to Use this Document
in Your State

Connection to your state vapor intrusion
regulations or guidance
• Fate & transport modeling
• Indoor air modeling

Equipment compatibility requirements
• Storage tank programs
• Bulk transport requirements

Facility response plans
• Emergency response
• Spill Prevention Control and Countermeasures
(SPCC) plans
26
Training Roadmap
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Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
27
Biofuel Releases
(Section 2)
This section will cover
Release Scenarios
and Frequencies
Release Causes
Prevention
Emergency
Response Planning
Evaluated based on the differences
between petroleum and biofuel
supply chains
28
Petroleum vs. Biofuel Supply Chains
(Combined Figures 2-1 and 2-2)
Manufacturing
Refinery –OR– Facility
(Bulk)
Transport
Bulk Depot /
Supply Terminal
(Blended)
Distribution
Pipeline
Components
Truck
AST
AST
Rail
Piping &
Manifold
Piping & Manifold
Dispensing
Station
UST System
UST
Product Piping
Truck
Loading Rack
Barge
Unloading /
Loading Rack
Dispenser
29
Release Scenarios and Incidents
(Section 2.1)
Transport
Rail
Truck
Barge
Volume and Incident Frequencies (Table 2-1):
Potential Volume
Incident Frequency
Tanker trucks: ~8,000 to 10,000 gallons
per truck
1,000 road accidents per
year (1 in 25,000 deliveries)
Railcars: ~25,000 to 30,000 gallons per
railcar; unit trains 70-100 cars
2,000 derailments per year
(severity not specified)
Tank barges: ~420,000 to 630,000
gallons per barge typical
2.16 gallons spilled per 1
million gallons moved

Pipeline
If all bulk gasoline and diesel currently
transported was used to produce E10
and B5, then bulk biofuels transport
needs would be:
• 1,250 tanker trucks,
• 415 railcars, or
PER DAY
• 20 tank barges
Distribution
Truck
30
Release Causes
(Section 2.2)
Leak Detection Issues, Release Causes (Table 2-2):
Equipment
Detection
Causes
Underground
Storage Tank
(UST) System
Small volume or chronic
releases may not be
detected if commercial
leak detection equipment
is incompatible
Incompatible materials;
solvent nature of
biofuels scouring
sediment, sludge,
rust, and scale built up
in tank previously
storing conventional
fuels
Acute, large volume
releases detected
through automated
volume reconciliation
accounting
Dispenser
System
Small volume or chronic
releases detected
through standard
inspections
Incompatible materials;
filters plugging due to
insufficient rate of
changeouts
Dispensing
Station
UST System
UST
Product Piping
Dispenser
31
Selected Biofuel Release Information
(Table D-2, Appendix D)
Site
Fuel
Volume in gallons
(Section 2.1)
Causes
(Section 2.2)
PNW Terminal, OR
DFE
19,000
AST release
Maxville, Ontario
Balaton, MN
South Hutchinson, KS
Cambria, MN
Storrie, CA
Rockford, IL
Williams County, OH
DFE
26,000
60,000
28,000
25,000
30,000
55,000 – 75,000
80,000
Derailment
Wood River, NE
DFE
20,000
Loading railcar
Rice, MN
Hastings, MN
E85
700
800
UST release
St. Paul, MN
Biodiesel
29,000
AST release
See Appendix D: fate and transport evaluation (Section 3), analytes investigated
(Section 4), and response activities conducted (Section 5)
32
Release Prevention
(Section 2.3)


Compatible materials and equipment
• Plastics, polymers, and elastomers
• Metal components and solders
• Commercial leak detection equipment
Management practices
• Changing out filters more frequently can
ITRC, Biofuels-1, Figure 2-7
prevent clogging issues
• Proper Operations & Maintenance and
frequency on leak detection equipment
prevents undetected releases

Appendix B (checklist) provides guidance
on compatibility of UST systems for
biofuels
ITRC, Biofuels-1, Figure 2-5
33
Emergency Response Planning
(Section 2.4)

Applicable plans
• Spill Prevention Control and Countermeasures
(SPCC) regulations (40 CFR 112)
• Facility Response Plans (FRP)

Additional Emergency Response considerations
•
•
•
•
Common fire-fighting foams – less effective
Appropriate foams – less available
Sorbent booms – miscibility, sorption, etc.
Impacts to sensitive receptors – oxygen demand,
biodegradability, etc.
34
Our Case Study: The Release
Release Volume (Section 2.1)
10,000 gallons E85 released from a UST that
was switched from storing E10
Release Cause (Section 2.2)
E85 scoured the sludge, rust,
sediment, & scale
Release Prevention (Section 2.3)
Guidance on converting tanks to E85 NOT used
35
Biofuel Releases Summary
(Section 2)

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
Biofuel releases will occur somewhere along the supply
chain
Current case studies (Appendix D) indicate they occur
more often in association with bulk transport or during
storage
Frequency is likely to increase as storage and handling
increases
Root causes are often materials compatibility and
management practices associated with equipment
Can be addressed to prevent releases such as using the
tank conversion checklist (Appendix B)
Resources for emergency response preparedness are
also available
36
Training Roadmap

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

Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
37
Fate and Transport
(Section 3)
This section will cover:
Biofuel
Properties
Surface and
subsurface
behavior
Effects on microbial
communities and byproduct formation
Impacts on petroleum
hydrocarbons and
NAPL
Use of the hypothetical case
study to help illustrate key points
38
Properties of Selected Fuel Components
(Table 3-1)
Solubility
(mg/L)
Henry’s
Vapor
Law
Pressure
Constant
(mm Hg)
(unitless)
Biodegradation
Potential
Implications
Ethanol
Infinite
2.1E-4 to 59
2.6E-4
Aerobic: hours to
days
Anaerobic: days
to weeks
Readily partitions to water
and dilutes according to
availability. Rapidly
biodegradable
Benzene
1,800
0.22
Aerobic: days to
months
Anaerobic: years
Readily partitions to vapor
phase from NAPL and
from water

75
Summary of some of the more pertinent properties of biofuels and
reference compounds (benzene and diesel)
• Provides a generalized summary of implications relating to these
properties
• Expanded property table available in Appendix C of the document

Table excerpts provided for the E85 case study
39
Behavior in Surface Spills
(Section 3.5.1 and 3.5.2)

Initial fate can be controlled by
•
•
•
•

Vaporization
Ignition and consumption by fire
Surface drainage
Surface water dilution
Immediate short-term impacts on surface water biota
• Aquatic species toxicity (Section 1.6)
 Ethanol and isobutanol: aquatic toxicity values range
from 1,000 mg/L to > 14,000 mg/L
 Biodiesel: numerical values currently not available (area
of research)
• Dissolved oxygen depletion
 Can result in detrimental impacts to aquatic life (i.e. fish
kills)
40
Behavior in the Subsurface:
Petroleum Hydrocarbons (Figure 3-1)
ITRC LNAPL guidance and training available for
additional information on LNAPL distribution –
www.itrcweb.org/LNAPLs
Trapped and sorbed residual
Volatilization
NAPL
body
Dissolved phase plume
Aquifer
Groundwater
flow direction
Groundwater source (longer term)
Capillary fringe
Unsaturated zone
Primary source (short term)
41
Behavior in the Subsurface:
Ethanol Blends (Figure 3-5)
Conventional
gasoline (E0)
E10
DFE
High permeability
water-filled lens
Pore water
containing ethanol
Immobile gasoline
phase
capillary
fringe
aquifer

(collapsed)
capillary fringe
Dissolution to
groundwater
Ethanol blends behave differently than low solubility biofuels or
petroleum compounds
• Ethanol fraction will partition into soil moisture present within the vadose
zone and capillary fringe
• Once in contact with groundwater, will migrate
• Likelihood of ethanol reaching groundwater is dependent on release
scenario (large spills more likely to reach water table)
42
Potential Media Impacts by
Equipment Type (Table 3-2)


Table objective: provide information regarding potential release
points, release volumes and media that can be affected by release
Example for E85 case study (UST release)
Equipment Type
Potential Media Impacts
Underground storage • Surrounding backfill and soil in the UST “pit”
tank systems
• Groundwater impacts depend on the proximity of the
(Section 2.2.5)
water table to the UST as well as a sufficient driving force
to cause the biofuel to percolate to depth
• Dispensing stations
• If groundwater is impacted, cosolvency issues may be
• May be present at
present if historic petroleum releases have occurred at
manufacturing
the same location
facilities and bulk
depots/supply
terminals
43
Biochemical Oxygen Demand
(Section 3.3.2.2)

Release of biofuel into
an aqueous
environment will result
in rapid consumption of
dissolved oxygen (DO)

In groundwater, rapid
biodegradation will
induce anaerobic
conditions
Dead paddlefish resulting from a
release of Wild Turkey Bourbon
44
Biofuel Biodegradation
(Figure 3-2)

Biofuels more readily biodegradable
Methane
CO2
H2
Ethanol
CO2
Acetyl CoA
Butyryl CoA
AcetoacetylCoA
Butanol
Butyrate
CO2
Acetone
Acetate
Methane
Figure 3-2. Major routes of the
anaerobic fermentation of ethanol
45
Factors Affecting Biodegradation


Inhibition of biological degradation at high
concentrations (6% - 10% ethanol)
Rate affected by
• Available electron acceptors
• Nutrients
• pH (optimal = 6-8)
 Production of volatile fatty acids during metabolism
can lower pH
46
Methane Hazards
(Figure 3-4)
Methane is a
flammable gas
• Lower explosive limit (LEL)
= 5% in atmosphere
• Upper explosive limit (UEL)
= 15% in atmosphere

LEL equivalent
concentration in
groundwater
• 1 - 2 mg/L
• Dependent on temperature
Figure source:
30 CFR 57.22003
20%
16%
Oxygen

Mixtures which cannot be
produced from methane
and air
Explosive
Capable of forming
explosive mixtures
with air
12%
8%
Not capable of
4% forming explosive
mixtures with air
0
0
4%
8%
12%
16%
20%
Methane
Relationship Between Quantitative Composition
and Explosivity of Mixtures of Methane and Air
47
Generation of Methane

Methanogens utilize acetate
and hydrogen
• Partitioning between
dissolved and gaseous
methane concentrations
• Dissolved methane
concentration dependent on
groundwater temps


Delays (months to years) in
methane production have
been observed in both lab
and field studies
Methane soil gas may
undergo attenuation in the
vadose zone
Estimated Soil Gas Methane (%)
(Figure 3-3)
100
80
60
40
Temperature (70oF)
Temperature (45oF)
20
0
0
10
20
30
40
Dissolved Methane (mg/L)
48
Preferential Biodegradation of Biofuels
Over COCs (Section 3.4.3 and 3.4.4)




Readily degradable nature of biofuels can result
in preferential biodegradation of biofuels over
COCs
Plume elongation expected to be temporary
Elongated plumes may have shorter lifetimes
because of lower concentrations of petroleum
hydrocarbons and buildup up biomass
Redox changes in the subsurface may lead to
changes in the mobilization of metals
49
Enhanced Solubility of Petroleum
(Section 3.4.1)

Some biofuels can act as cosolvent
• High concentrations (> 20% ethanol)
• May occur within capillary fringe
• Unlikely to occur in groundwater

Releases of highly soluble biofuels (e.g. ethanol)
onto prior hydrocarbon releases
• May result in mobilization of pre-existing residual
separate phase hydrocarbons
• Section 3.4.2
50
Our Case Study: Fate & Transport

Media impacts to
vadose zone, capillary
fringe and
groundwater
• Capillary fringe can
act as a lingering
source area for
ethanol

Groundwater will
become anaerobic,
possibly leading to
methane generation
CH4
51
Fate and Transport Summary
Property differences between biofuels and petroleum fuels
influence fate and transport in the environment






Highly soluble biofuels readily partition into water
Biodegradable nature of biofuels significantly impacts
dissolved oxygen concentrations
Ethanol can be retained in the capillary fringe (lingering
source)
Cosolvency effects likely limited to capillary fringe and large
E95 releases
Potential for significant methane generation
Temporary plume elongation
52
Training Roadmap








Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
53
Training Roadmap








Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
54
Site Investigation
(Section 4)
This section will cover:
Risk
Drivers
Monitoring
CH4
Analytical
Methods
Site Closure
Considerations
Use of the hypothetical case
study to help illustrate key points
55
Risk Drivers for Site Investigation

Surface water
• Ethanol can not be recovered due to solubility; biodiesel can be
recovered like petroleum
• Dissolved oxygen depletion – risk to aquatic species a significant
new concern

Vadose zone
• Explosive risk from increased methane production – NO ODOR
• Potential increased vapor intrusion (VI) risk for petroleum VOCs

Groundwater
• Risk to drinking water supplies due to plume elongation
• Biofuel degradation can produce taste and odor issues in
drinking water supplies
56
Our Case Study: Site Investigation
(Section 4)
Site investigation strategy:
• Dependent on age, volume,
composition of release
• Potential risk receptors

Case study:
• Recent E85 spill
• Dispensing station
building and
surrounding residential
area
CH4
57
Site Investigation – What’s Different

Different chemical and physical properties of
biofuels require changes to investigation design
• Monitoring well screen length and type
• Additional analytical parameters

Additional vapor risk assessment for VOCs and
methane (if receptors are present)

Time factor
• Longer monitoring duration needed to assess risk
58
Methane Monitoring (Section 4.1.1)

Biofuels have the potential to generate significantly more
methane than petroleum

Initial evaluation should determine if explosive
conditions exist

Methane appearance may not be immediate, suggesting
extended monitoring when receptors are present
• Low or no initial methane may not mean no future risk
• May appear without detection of source biofuel

Subsurface methane may be sampled in:
• Soil gas using push probes or vapor points
• Groundwater using push probes or wells for dissolved
methane
59
Methane Monitoring (Section 4.1.1)

Groundwater
• Generally more reliable than soil gas for detection
• Well screen lengths may affect concentrations
• Must closely follow QA/QC sampling procedures
• Methane is easily lost during sampling
• Levels above 25 mg/L indicate saturated levels where
ebullition (bubbling) may be occurring

Soil gas
• Sampling points and procedures same as VOCs (ITRC
2007, Vapor Intrusion Pathway: A Practical Guideline)
• If potential receptors are present at least one vapor
monitoring point should be placed in the release area
60
Delayed Methane Generation: Cambria, MN
Case Study July 2007 (Appendix D)
61
Delayed Methane Generation: Cambria, MN
Case Study December 2007 (Appendix D)
62
Ethanol Monitoring (Section 4.1.2)

Vadose zone
• Soil gas monitoring same as VOCs
• Soils can be sampled using standard VOC methodology

Capillary fringe
• Lysimeters have been used, but sampling capillary fringe not
necessary

Groundwater
• Shorter monitoring well screens recommended to capture ethanol
draining, and/or leaching from the capillary fringe
• Multi-level wells may be needed
• Detection of ethanol in groundwater should not be used alone for
methane risk assessment
63
Cambria, MN Case Study
Soil Sample
6,340,000 ug/kg
Ethanol
Aq. Ethanol
Capillary fringe
MW-20 (5’ screen)
6,100,000 ug/L
Groundwater
MW-1 (10’ screen)
ND
Note: Not in ITRC document
64
Biodiesel Monitoring (Section 4.1.3)

Biodiesel forms a LNAPL on groundwater
• Wire wrapped screens are recommended to help facilitate the
entry of higher viscosity biodiesel LNAPL into monitoring wells
• TarGOST (LIF) has been shown to effectively map B100 NAPL

No standard analytical methods for biodiesel in soil or
groundwater exist but surrogates can be used
• Bugs immediately hydrolyze FAMEs to fatty acids
• TOC/DOC and COD to quantify dissolved fraction in groundwater
• TOC can also be used to quantify biodiesel in soil
• Degradation products (e.g. short chain fatty acids)
• Surrogates do not directly quantify the concentration of biodiesel,
but are useful to evaluate groundwater impact and methane
generation potential
65
Biodiesel Monitoring (Section 4.1.3)

Biodiesel (B100) produces a lot of methane (and CO2)

Like ethanol ebullition (bubbling)
may increase methane risks,
and VI risks for blended fuels

1.4L FAME → 662 L methane

Biodiesel also has a
taste/odor/appearance impact
on water quality

Petroleum fraction of blends may be the risk driver for
biodiesel blends; however methane may still be an issue for
higher percentage blends
66
Surface Water Monitoring (Section 4.1.4)



Depletion of dissolved oxygen and the affect on aquatic
life is primary concern with soluble biofuels (e.g. ethanol)
DO may be measured directly in the field
COD, DOC and/or TOC may be used to assess the
potential oxygen consumption load
67
Field Screening Methods
(Table 4-1)
Table for Sampling and Analytical Methods (Table 4-1)
Analyte
Environmental Media Analytical Methods
Field Methods
Methane
Soil Gas
Infrared landfill gas meter
Methane (LEL)
Soil Gas
Explosimeter
Ethanol/butanol
Soil Gas
Photoionization detector
DO
Surface Water
Field meter, kit, or titration
BOD
Surface Water
Field meter or kit
68
Analytical Laboratory Methods
(Table 4-1)
Analyte
Environmental Media Analytical Methods
Methane
Soil Gas
USEPA 3C; ASTM D1946
Dissolved Methane Groundwater
RSK-175
Acetate
Groundwater
Ion chromatography, other
DOC/TOC
Surface Water, Soil,
Groundwater
Standard Method 5310C;
ASTM D513-6; USEPA 415.3
BOD/COD
Surface Water
USEPA Methods 405.1
(BOD); 410.1 #DR/3000
(COD), or similar
Ethanol/butanol
Soil
USEPA 8260B
Ethanol/butanol
Soil Gas
USEPA Method TO-15
Ethanol/butanol
Groundwater
USEPA 8260B; USEPA 8260;
USEPA 8015C; USEPA
8261A
69
Our Case Study: Site Investigation



Monitor soil gas
near receptor
(CH4, VOC)
Install vapor point near
receptor
Shorter-screened
wells in source area
Monitoring for
additional parameters
CH4
Use shorter
screened wells in
source area
Monitor the
groundwater
(diss. CH4, EtOH,
VOC, Acetate
70
Site Investigation Summary
(Section 4)





Methane in soil gas = likely risk driver
Physical properties of biofuels may require some changes
to a site investigation design, such as monitoring wells
Sampling for additional parameters will likely be required
Additional field screening equipment may be required
Additional VI monitoring may be required due to
• Stripping of petroleum VOCs from groundwater and advection of
petroleum vapor by methane and other biogenic gases
• Methane exerts a large oxygen demand which can allow petroleum
vapors and methane to migrate further

Site investigation of other or new biofuels should be based
on the physical, chemical, and biological properties of the
biofuel
71
Site Closure Considerations

Was the site investigation adequate for a biofuel release?

Have all groundwater and vapor risks been identified?

Are degradation products still present in groundwater (e.g.
methane, acetate)

Has monitoring adequately accounted for delayed
methane generation?

If elevated risks and hazardous conditions exist,
remediation may be required
72
Training Roadmap








Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
73
Long-Term Response Strategies
(Section 5)
This section will cover:
General
considerations
for remediation
Risk
management
Remedial
selection
CH4
Use of the hypothetical case
study to help illustrate key points
74
Our Case Study: Long-Term
Response Strategies (Section 5)
Requires consideration of:
Case study:
• Type of biofuel
• Extent and magnitude of the
• E85 spill
• Media impacted:
• Vadose zone
• Capillary Fringe
• Groundwater
• State regulations applicable to
release
• Regulatory threshold for a
COC(s)
• Risk to identified receptors
gasoline components
• Dispensing station building and
surrounding residential area
CH4
75
Generalized Framework
(Figure 5-1)
Site Conceptual Sections
3 and 4
Model/Site
Characterization
Sect 5.1 Above
regulatory
threshold and/or a
potential hazard
exists?
Yes
Risk Sect 5.2.1
acceptable or
No
manageable w/
controls?
Sect 5.2.2
Implement closure
Sect 5.3.3
monitoring and/or
controls
Meet
Sect 5.4
No Further
Action/Site
Closure
Yes
Active
Remedy
Yes
Yes
No
Sect 5.3
Meet
closure
requirements?
No
remedial
endpoints?
Yes
No
76
Risk Management
(Section 5.2.1; Table 5-1)


Management of risk through long-term monitoring
Controls (institutional or engineering)
• Provide protection from exposure to contaminant(s)
Implement closure
monitoring and/or
controls
that exist or remain on a site
Benefits
Limitations
Dissolved
biofuel is
readily
biodegradable
without
additional
enhancement
• High concentrations of some dissolved biofuel constituents (i.e.,
ethanol) can be toxic to microorganisms
• Delayed biodegradation of more recalcitrant contaminants via
preferential biodegradation of the biofuel
• Does not address immediate risks
• High potential for methane generation
• Does not address LNAPL, although microbial processes can
enhance dissolution in groundwater
• Surface water may become anoxic, impacting aquatic species
and habitat
77
Selection of Remedial Technology
(Tables 5-2 and 5-3)





Active remedy
• Eliminate or reduce the remediation driver or COC
Remedial technologies
Active
• Soils/Sediment (Table 5-2)
Remedy
• Groundwater/Surface water (Table 5-3)
Categorized as in situ or ex situ
Subdivided within each category by dominant remedial
mechanism
• Biological technologies (e.g. enhanced aerobic biodegradation)
• Chemical (e.g. chemical oxidation)
• Physical (e.g. soil vapor extraction)
Provides discussion on overall benefits and limitations of each
technology to help guide selection
78
Remedial Technology (Soils Example)
Table 5-2

Examples applicable to E85 impacts to
vadose zone/capillary fringe
Technology
Active
Remedy
Benefits
Limitations
Rapidly removes readily strippable
compounds (constituents with a high
Henry's Law Constant, vapor pressure,
and/or biodegradability). Promotes
aerobic biodegradation of biofuels and
methane oxidation (if present).
Not effective for constituents
with a low Henry's Law
Constant, vapor pressure,
and/or biodegradability; may
require ex situ vapor
treatment.
Can result in rapid elimination of
dissolved constituents and increase in
dissolution and subsequent
biodegradation of residual NAPL.
Promotes methane oxidation. Likely
inhibits formation of anaerobic conditions
and methane generation.
Does not directly address
LNAPL. High concentrations
of some dissolved biofuel
constituents (e.g. ethanol)
can be toxic to
microorganisms.
Physical
In Situ Treatment
Soil vapor
extraction
(SVE)
Soil
Biological
Enhanced
Aerobic
Biodegradation
Bioventing - soil
79
Detailed Remedial Technology Tables
(Tables 5-4a through 5-4c)





Biofuels evaluated
Active
Remedy
• Ethanol (Table 5-4a)
• Butanol (Table 5-4b)
• Biodiesel (Table 5-4c)
Identifies targeted environmental media
Evaluates technology by specific property (e.g. solubility) and
provides numerical values
Compares efficiency to a reference petroleum hydrocarbon
compound
Summarizes which compound (biofuel or reference
hydrocarbon) is favored by the remedial technology
80
Example Table 5-4a
(Figure 5-2)
Expanding on the examples selected from Table 5-2 as
applicable to vadose zone remediation of the E85 case study:
Technology
Target Media
VZ GW
SVE
X
Bioventing
X
Depicts the
media that the
technology is
applicable to
Active
Remedy
P/C/B Properties
Benzene
Ethanol
Favors
Vapor Pressure
75 mm Hg
49 -56.6 mm Hg
Benzene
Aerobic Bio Potential days
hours
Ethanol
Aerobic Bio Potential days
hours
Ethanol
SW
Describes what
physical, chemical
or biological
properties are
affected by the
technology
Property values for
benzene (reference
compound for
ethanol)
Property
values for
ethanol
Describes which compound the
technology favors with respect to
the targeted property
81
Example Table 5-4d (Methane)
Evaluates technology effectiveness on methane
remediation versus methane generation
Technology
Target Media
VZ GW
SVE
X
Bioventing
Depicts the
media that the
technology is
applicable to
X
Active
Remedy
P/C/B Properties
Methane
Remediation
Methane
Generation
Vapor Pressure
Applicable
N/A
Aerobic Bio Potential
Applicable
Inhibits
Aerobic Bio Potential
Applicable
Inhibits
SW
Describes what
physical, chemical or
biological properties
are affected by the
technology
Evaluates
whether
technology can
remediate
methane, and
by which P/C/B
property
Specifies whether
technology inhibits
methane
generation, and by
which P/C/B
property
82
Our Case Study: Long-Term
Response Strategies

Application of SVE for vadose
zone:
• Physical removal
• Enhanced biodegradation

Long-term monitoring for both
soil gas and dissolved plume
to assess and re-evaluate risk

Additional technologies can
be evaluated/implemented
CH4
83
Long-Term Response Strategies
Summary




Response strategies should be based on risks
presented by biofuel release
MNA may be a viable response strategy
If methane is a concern, longer-term monitoring
and/or engineering controls may be warranted
Technology evaluation process can be applied to
biofuels, the petroleum component of the blend,
and future biofuels
84
Training Roadmap








Introduction
Releases
Fate and Transport
Q&A Session #1
Site Investigation
Long-Term Response Strategies
Summary
Q&A Session #2
85
Our Case Study: Summary







Equipment compatibility
issues
Biofuels fate & transport in
the environment
Methane gas generation
Site investigation design
Monitoring in
environmental media
Long-term response
strategies
Risk management
CH4
86
Overall Summary

Biofuel production and consumption is increasing
= increase in potential frequency of releases
= potential for environmental impacts

By using the ITRC document, you will be
prepared and able to:
•
•
•
•
Build a better Site Conceptual Model (SCM)
Understand fate & transport in the environment
Know how to investigate a biofuel release site
Formulate a better response strategy
87
Thank You for Participating

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
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• http://www.cluin.org/conf/itrc/biofuels/resource.cfm

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• http://www.cluin.org/conf/itrc/biofuels/feedback.cfm
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